1. Field of the Invention
The present invention relates to an image forming apparatus, which serves as an electronic copying machine, equipped with a duplex device enabling the copying of both sides of a paper.
2. Description of the Related Art
There is a model of an image forming apparatus, which is an electronic copying machine, provided with a so-called duplex copying function to copy an image on one side of a paper and then, copy another image on the other side.
This kind of an image forming apparatus is equipped with an automatic duplex device which takes a paper with a developer image fixed on one side by a fixing device once via an auxiliary conveying path, inverse it to change its fixing side and carrying it out again between a photo-conductive drum and a transfer charger.
To be concrete, there is a converting (sorting) gate between a fixing device and a paper receiving tray and this paper receiving tray is arranged at one of the sorted destinations and the automatic duplex device is arranged at the other sorted destination via the auxiliary conveying path.
An electronic copying machine equipped with such the automatic duplex device adopts such a structure that, in order to suppress the increase in the installing space of the main body, the automatic duplex device is arranged almost immediately below the fixing device and these fixing device and the automatic duplex device are connected each other by the auxiliary conveying path.
The auxiliary conveying path is formed in a sharp curved state so as to convey a paper almost in a U-turn state. As a result, such a phenomenon called a jam that a paper is jammed in the auxiliary conveying path tends to be caused.
As the indication of "JAM" is shown on the operation panel at this time, worker is required to remove a jammed paper. Actually, the length of the auxiliary conveying path is shorter than that of a paper and a part of a paper left in the auxiliary conveying path and the remainder of the paper is left in the fixing device and/or the automatic duplex device.
The fixing device and the automatic duplex device are so arranged that they can be pulled cut of the main body, while the auxiliary conveying path comprising conveyor rollers and guide plates is fixed to the main body.
So, worker pulls out the fixing device or the automatic duplex device to this side and remove a jammed paper or takes out the jammed paper by inserting his hand into the main body and takes out the jammed paper without pulling out the devices.
However, even when the fixed device and the automatic duplex device are pulled out, as a part of a paper is left in the auxiliary conveying path in the main body, the paper tends to be cut in the main body. If so, the portion of the paper left in the main body must be taken out and it becomes very troublesome to take out the paper left in the main body.
If the hand is inserted into the main body from the first or later, the inside of the main body is not visible and there is the possibility that the hand may touch other component elements and is injured or other component elements may be damaged.
Further, there are some models in which a fixing device and an automatic duplex device are arranged in series along a paper conveying path and an auxiliary conveying path is omitted. Even in this case, such devices are separately taken out if a paper is jammed and there are the same problems as shown above.